Electrolytic condenser



April 1 1924. 1,488,560

J. SLEPIAN ELBCTROLYTI C CONDENSER Filed Dec. 30, 1919 Flya INVENTOR IfJarep/z Slepz'arz WITNESSES:

I i i- B A ORNEY invention 2 will be m'or fully des tribe Patented Apr.1, 1924.

UNITED STATES JOSEIH SLEPIAN, OF WILKINSBURG, PENNSYLVANIA.

ASSIGNOB T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, Aconron-ArIo'N or rENNsYLvANIA.

ELECTROLYTIC CQNDENSER.

Application filed December 30, 1919. Serial No. 348,451.

To all whom it may concern:

Be it known that I, Josnrn SLEPIAN, a citizen f the United States, and aresident of lllilkinshurg. in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Electrolytic(.oudensers, of which the following is a specification.

My invention relates to electrolytic condensers and, more particularly,to .condens ers of the type formed byemployinga plurality offilm-forming electrodes immersed in a suitable electrolyte}and-it;h'as,lfor its primary object the construction of condenser s'oftheabove'designated type which shall be particularly suitable-; -forapplication in variable-voltage, alternating-current cir Cuitsj i. r Ihave-' found-that cohdenlsers which are suitable for constaiiflvoltagecircuits do not continuously 5 operate "-s'jatisfactorily when employedin variable-voltage circuits. jWhe-n the condensers'are subjected toa-yariable voltage, their capacitance 'cliaiiges-whiclniin general,results in a change of 'power factor and, if the condensers remainunattended for any length ofti'me, with the conditions changing in this?manner; f the electrodes thereof deteriorate,' whichsoon f precludesfurther use of the condenser'.

One object of my invention, therefore, re sides in the. provisioiiofmeans for maintaining: a substantially constant capacitance and arelatively low value origawerracter-jn an electrolyticcondenserchniiected in a fiari able-voltage, 'alternatingurrentworkingcil'diiit. 31": I:

With these and other objects in viia;i

named; in the drawingsf-im'the' salami views of whichoorrespondliig'numerals in;

dicate' like parts; and then particularly pointed out in the claims. r I

In the drawings; Fig. 1 is aidiagrammatic view of an electrolyticcondenser provided; with'a'dditional electrical equipment to maintaintits capacitance substantially constant, nd- Fig 211ml 3 ar mil f diagrma i views of condenfifs whihli illustrate a'inodi ca-t n imyi ye t am wrein mmo-1 tance of the condenser-is maintained substantially: constantby electrical equipment which provides, an inherent, regulation.

I have found that a satisfactory elect-r0 lytic condenser may beconstructed by em rect current {not shown).

ploying additional or auxiliary film-forming electrodes, which arepreferably of smaller area than the main electrodes. By impressinq ahigher potential on the. auxiliary electrodes, I have found that themain electrodes may be maintained in good operating condition. heauxiliary electrodes'maintain the main electrodes in good operatingcondition by insuring that the'voltage of the main electrodes shallalways be positive with respect to the electrolyte. The good resultsobtained by employing auxiliary electrodes; however. are offset, to agreat extent, if the condenser is subjected to a variable voltage. Inorder to maintainthe advantage of the auxiliary electrodes andconsequent good operating; conditions, I have found that the voltageimpressed onthe auxiliary electrodes should be varied with variations inthe voltage of the supply circuit. The voltage'adjustment may beobtained in various ways and, in order to illustrate the application ofmy in vention, I-have shown several structures, all. of which embody thesame general principles. It should be understood that the structuresshown and the description thereof apply to electrical conditions whereinthe appliedvoltage is varied but the frequency is; constant. I

IifFigxl is'shown a condenser compris-- ing'a tank' 1 containing asuitable electro- 1 %;2 in which a plurality of main elect-rodes '-3 a dt and a plurality of auxiliary electrodes 5=hnd 6 are immersed. T heelectiode' 3 is connected to a tap? onthe secondary winding 8 of atransformer 9, the

primary winding 10 of which may be connected to 'an alternating-currentsupply cirsuit (not-. shown). The main electrode 4 is connected, througha plurality of series coils 11 of a relay device 12, to anothertapdi, onthe seccndarywinding 8. A. plurality of voltage coils 1ft are'connected'in parallel relation to the condenser and to the secondary winding 8.The relay device 12 has alvanelb which is connected to actuate 'acontact arm 16 that is adapted to engage contact members 17 au'd 18 Thecontact members 17. and 18 are respectively connected to terminals of .abalance coil 19, which may be connectedto source of di- The auxiliaryelectrodes 5 and 6 are connected to movable contact members 20 m unted Pa Suitably supported feed-screw 21 that is connected to a reversingmotor 22. The reversing motor 22 has one armature terminal connected tothe contact arm 16 and the other terminal to the mid-point of thebalance coil 19. A field winding 23 of the motor 22 is connected acrossthe source of direct current to provide a separate excitation therefor.

An examination of the relay device 12 will disclose that the seriescoils 11 and the voltage coils 14 tend to establish magnetic fields atright angles to each other, under normal conditions; that is, when thestrengths of magnitudes of the fields are substantially the same. Whenthe magnetic fields are at right angles to each other, there is acomponent force established at 45 to each of the fields, whichdetermines the position of the vane 15 when balanced conditions obtain,as shown in the drawing. Under this condition, the contact arm 16 issupported midway between the contact members 17 and 18, but when normalconditions do not obtain in the condenser, the magnetic fields of therelay device are unequal and cause the vane 15 to move rotatively andthus move the contact arm 16 into enga ement. with one of the contactmembers 1 and 18. Thedirection of rotation of the reversing-motor22isdet-ermined by the connections established by the contact arm 16. Whenthe contacta-rm 'is shifted from one contact memberto the'othericontactmember, the direction of rotation of the motor 22 is reversed,.avhichdetermines the direction. in whichgthe contact -members 20 aremoved, ,the connections oi the auzril: iary. electrodes; 5' and .216,to-,.-the;, secondary winding 8 bein thus varied. h

I have found that the ca acitance -oi an electrolytic condenser, provied with auxiliary electrodes, dependsboth upon the alternating voltageof the working circuit to which the condenser is connected and upontheiamount by which the voltage of the auxiliary; electrodes is raisedabove that of the main electrodes...-I have-found, in eneral, that, ifthe. voltage in the workin a ternat: ing-current-circmt is raised, thisuse may be compensated 7 by dccreasin the excess voltage between theauxiliary, efiactrodes and the main electrodesx; If, the excess. voltageimpressedzupon the auxiliary'electrodes 1s properly varied, the caacitance ofthe: condenser may be kept su bstantially constant, itspowerfactor-relativelylow and along lifeinsured. The construction shown inFig. 1. provides for variations in the voltage im resscd u on the.auxiliary electrodes, which variations are governed by the relay device12, which, in turn, is governed by the voltage impressed upon thecondenser.

For example, in case of a rise of voltage in the alternating-currentworking circuit,

the contact members 20, which connect the auxiliary electrodes to thesecondary winding, should he moved to include a lesser number of turnsbetween the auxiliary electrodes and this adjustment should be continueduntil the tendency of the capacitance of the condenser to decrease hasbeen obviated. Similarly, in case of a decrease in the impressedvoltage, the contact members 20 are moved away from each other, or toinclude a greater number 01 turns between the auxiliary electrodes,until there is no tendency for the capacitance of the condenser toincrease. It will be appreciated that various means for regulatin" theconnections of the auxiliary electrodes to the secondary winding 8 maybe employed to obtain the desired. results. For example. the connectionsof the auxiliary electrodes to the secondary winding may be madepermanent and the connections of the main electrodes may be madevariable, or all of the connections of the electrodes of the condenserto the secondarywinding may be made variable to maintain the desiredratio betweenthe exciting voltage and the im pressed or working voltage.1

In Fig. 2 is shown a modification of my invention comprising a condenser24 having a-tank 25 containin an electrolyte26 in which are immersed aplurality ofcmain electrodes 27 and 28,-to 'ether with an auxiliaryelectrode 29, all 0? film-forming material. The electrode 28 isconnected toone side of an alternating-current working circuit 30,.andnthe electrode 27 is connected, through a primary windin' 31 of'atrans former 32, to the other si e of the circuit 30. The auxiliaryelectrode 29 is connected through a secondary, winding 33 of thetransformer 32,.to ,the electrode .27 as indicated-at;34. .In ,thecondenser a ove.de-. scribed, the .voltageregulation is inherent and nomovableapparatus is re?uired,. The excess voltage impressed upon t 1eauxiliary electrode 29 is. determined by the current.

traversin the winding 31 to the main-elec .conditions were changed. Itis clear, there fore, with the connections shown in Fig. 2, that,sincethe current in the main electrodes remains substantially constant,the

excem voltage impressed upon the auxiL' the tendency of the condenser tovary in capacitance with a variation in the impressed Volta e.

In ig. 3 the condenser is shown connected to the supply circuit in asimilar man ner to that shown in Fig. 2. As here shown, the electrode 28is connected to one side of the supply circuit 30, and the electrode '27is connected, through the primary winding 31 of the transformer 32, tothe other side of the supply circuit. The auxiliaryelectrode 29,however, is connected, through the secondary winding 33 of thetransformer 32, to a secondary winding 34 of another transformer 35 tothe same side of-the supply circuit 30 as the 'main electrode 27. Theprimary winding 36 of the transformer 35 1s=connected, in parallelrelation, to the supply circuit30. As indicated in the drawing, thesecond ary windings 33 and 34: are rovided with a greater number ofturns t an their rehigh voltage to spective primary windings. The turnsof the transformer windings are so chosen for a definite ratio ofcondenser current and impressed voltage that the resultant voltageimpressed upon the auxiliary electrode has azero value. It is obviousthat a slight change in the ratio of condenser current and impressedvolta e will cause a relatively he impressed on the auxiliary electrode29. The instantaneous directions of the voltage existing in thesecondary windings 33 and 34 are chosen to be such that a decrease inthe ratio above mentioned will cause a decrease in the impressed voltageon the auxiliary electrode and that an increase in this ration willincrease the voltage impressed thereon.

It is apparent that my invention is not restricted to any particularform of apparatus because the broad principles may be applied by theemplo ment of various structures to accomplish t e desired results. Myinvention broadly com-prehends the variation of voltage impressed uponthe auxiliary electrodes to compensate for variations of the supplyvoltage or the voltage impressed upon the condenser and to maintainsubstantially a constant capacitance in the condenser. As mentionedheretofore, it is under'stood that the descriptions of the connectionsof the condenser are intended to be applied to condensers connected inalternating-currcnt circuits in which a substantially constant frequencyobtains.

The present application describes an mvention which is closely relatedto that described in my copending application, Serial No. 348,452, onelectrolytic condensers, filed December 30, 1919.

Although I have shown and specifically described a plurality ofcondensers connected in various ways to" an alternating-current workingcircuit to obtain a substantially constant capacitance: and goodoperating conditions, it is obvious that minor changes may be madein theadditional electrical equipment and in theconnections thereof withoutdeparting from the spirit or scope of my invention, and I' desire,therefore, that no' limitationsshall be imposed except such as areindicated in the appended claims.

* I claim asniy invention 1. A'n' electrolyticcondenser comprising aplurality of main'selectrodesand a'aplural-ity of auxiliaryelectrodes,all immersed in a suitable electrolyte, meansfor impressing a-higheralternating potential on the auxiliary electrodes than on the mainelectrodes, and means for varying'the excess potentialv between theauxiliafry electrodes and the main electrodes." 7

2.; An electrolytic condenser comprising a plurality ofmainrelectrodes,a plurality of auxiliary electrodes, all immersed in a suitableelectrolyte, means for impressing a higher potential on the auxiliaryelectrodes than on the main-electrodes, and means for varying the excesspotential between the auxiliary electrodes and the main electrodesgoverned by the potential impressed upon the condenser.

3. An electrolytic condenser comprising a plurality of main film-formingelectrodes, a plurality of auxiliary film-forming electrodes, allimmersed in a suitable electrolyte, means for impressing a higheralternating potential on the auxiliary electrodes than on the mainelectrodes, and means for so varying the excesspotential between theauxiliary electrodes and the main electrodes as to maintain thecapacitance of the condenser substantially constant.

4. The combination with a transformer having its primary windingconnected to an alternating-current supply circuit, of an electrolyticcondenser comprising a plurality of main electrodes connected to thesecondary winding of the transformer, a plurality of auxiliaryelectrodes so connected to the secondary winding as to include a largernumber of turns between the auxiliary electrodes than is includedbetween the main electrodes, and means for varying the number of turnsof the secondary winding included between the auxiliary electrodes.

5. The combination with a transformer having its primary windingconnected to an alternating-current supply circuit, of an electrolyticcondenser comprising a plurality of main electrodes connected to thesecondary winding of the transformer, a plurality of auxiliaryelectrodes so connected to the secondary winding as to include a largernumber of turns between the auxiliary electrodes than is includedbetween the main electrodes, and means for varying the number of turnsof the secondary winding included between the auxiliary electrodesgoverned by the voltage impressed on the primary winding of thetransformer.

6. The method of maintaining the capacitance of an electrolyticcondenser, that is connected to an alternating-current supply circuithaving a variable voltage and a substantially constant frequency,substantially constant, that comprises providing means for maintainingthe potential of the main electrodes always positive with respect to theelectrolyte, said means including an auxiliary electrode and varying thevoltage impressed on the auxiliary electrode with changes in the voltageimpressed on the condenser. i

7. The combination with an electrolytic condenser connected toanalternating-current supply circuit comprising a plurality of mainelectrodes and an auxiliary electrode, all immersed in a. suitableelectrolyte, of a plurality of transformers the primary winding of oneof which is connected to one of the main electrodes and the primarywinding of the other connected in parallel relation to thealternating-current supply circuit and the secondary windings connectedin series with each other and to the auxiliary electrode and to thesupply circuit.

8. The combination with an electrolytic condenser connected to analternatin -current supply circuit comprising a p urality of mainelectrodes, and an auxiliary electrode, all. immersed in a suitableelectrolyte, of a plurality of transformers, the primary winding of oneof which is connected to one of the main electrodes, the primary windingof the other is connected in parallel relation to the supplv circuit,and a plurality of secondary windings, each having a greater number ofturns than the respectivevprimary windings, connected in series witheach other and to the auxiliary electrode a-nd'to the same side of thesupply circuit as the primary winding which is connected to the mainelectrode.

9. The'combination with an electrolytic condenser connected to --analternating-current supply circuit, of means for maintainmg asubstantially constant capacitancewin cembe-r, 1919.

JOSEPH SLEPIAN.

otential mpressed

